LED lamp assembly

ABSTRACT

A lamp finding particular application in boat trailers and other vehicular applications is provided with a generally unbreakable lamp structure. The lamp preferably is provided with a plurality of LEDs arranged with rows and columns on a circuit card or board. The lamp is constructed by encapsulating the board and LED arrangement in a moldable lens material, which after removal from a suitable mold at least partially defines the lamp body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/521,808 filed Mar. 9, 2000, the contents of which areexpressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates generally to lamps, and more specifically tovehicle lamps having an array of light emitting-diodes (LEDs) providingthe light, and a structure and method of construction which produces alight structure that is relatively unbreakable and water resistantand/or water proof. While the invention is described in particular withits application in and to boat or other similar towed trailers, thoseskilled in the art will recognize the wider applicability of theinventive principles disclosed hereinafter.

One of the problems we have observed with respect to taillights ofvarious boat trailers and other towed trailers for example, and withrespect to vehicle lights in general, is the fact that the lights oftenbecome damaged. That is, it is not uncommon for a person who does notroutinely tow a boat trailer, to experience problems in backing the boattrailer, for example. Often in backing, the taillight of the trailerbecomes damaged. Likewise, boat trailers often are backed into water inorder to load or unload a boat to be carried or carried by the trailer.Because prior art light assemblies are not waterproof, water enteringthe light assembly can and often does damage the electrical capabilitiesof the light. We have developed a relatively low-cost, waterproof/resistant and relatively unbreakable back up and/or taillightand/or turning light, for example, that has wide application forvehicles, both driven and towed. In particular, we have found that alamp assembly can be molded completely from a suitable cellulosic,copolymer, polycarbonate, or acrylic plastic, and inserted in place ofconventional taillights on trailers and vehicles, for example.Preferably, we employ light emitting diodes (LEDs) as the source ofillumination for the light structure. The LEDs are mounted to a circuitcard or board in any predetermined arrangement. The board and associatedLEDs then are completely encapsulated or immersed in the material toform a solid, effectively one piece device during the manufacturingprocess.

While other lamp assemblies have employed LEDs in the past, the productsof which we are aware did not provide a light structure that isrelatively unbreakable alone or water proof/resistance in combinationwith the structure's other features. For purposes of this specification,relatively unbreakable means unbreakable in the environment of the lampassembly's intended use during expected or normal operating conditions.For example, we have found that Tenite® available from Eastman ChemicalCompany is an acceptable material for the lamp assembly of the presentinvention where the lamp assembly is intended for use in boat trailers.While the material mix employed for injunction molding may vary for theapplication illustratively described herein, we believe that thematerial preferably should have an impact resistance of 4.8 ft-lbs. perinch (ten percent (10%) plasticizer formulation). In boat trailerapplications, the material thickness may approach one half inch or more,for example, a thickness for which we were unable to find actualmanufacture's data. We have tested other polycarbonate material inprototype assemblies that has sustained 30 ft. lbs. force on the lightassembly without damage (tested by dropping a five pound weight from aheight of six feet). As indicated above, the preferred material for anyparticular application is one that does not suffer damage in itsintended application during normal or intended operation of thatapplication.

Among the devices of which we are aware that employ LEDs is onedescribed in U.S. Pat. No. 5,632,551 ('551). While employing LEDsgenerically, the '551 patent describes the use of a conventional lensand an associated metal housing. While recognizing that breakage is aproblem, the '551 patent attempts to solve the problem by recessing thelens member within the housing. While the invention described in the'551 may function well in some circumstances, it does not provide thesimplified solid structure, water proof/resistance construction and truenon-breakable design for light assemblies available with our invention.

BRIEF SUMMARY OF THE INVENTION

One of the objects of this invention is to provide a low-cost lampassembly;

Another of object of this invention is to provide a lamp assembly thatis relatively unbreakable in applicational use.

Another object of this invention is to provide a lamp or light structureemploying LEDs for the light source.

Another object of this invention is to provide an LED lamp structure inwhich the LEDs are arranged in rows and columns, the arrangement ofwhich permits LEDs emitting various visible light colors to be employedin the light structure.

Yet another object of this invention is to provide a lamp structure thatis directly replaceable with existing applications for similar lampsassemblies.

Another object of this invention is to provide a lamp structure thatexhibits at least water resistance capabilities for preventing damage toelectrical components of the structure.

Another object of this invention is to provide a lamp or light structureemploying reflectors.

Another object of this invention is to provide a circuit board whichallows air to escape during the molding process.

Another object of this invention is to provide a solid structure lampassembly.

Other objects will be apparent to those skilled in the art in light ofthe following description and accompanying drawings.

In accordance with this invention, generally stated, an unbreakable lampfinding particular application in automotive vehicle and trailers forexample, is provided in which the lamp body defines the lens and thebody itself Preferably, the lens and body is constructed from anunbreakable material, unbreakable being defined herein. The lampincludes a circuit board or card having a light unit associated with it.In the preferred embodiment, the light unit is a plurality of LEDsarranged in rows and columns. The lens and body material forms astructure which fully encapsulates in a solid integral part both thelight unit and the circuit board. Encapsulation provides at least waterresistance properties to the lamp assembly. The lens material is moldedin a predetermined manner to provide the body for the lamp assembly.

A method of constructing a lamp assembly in which the lens materialdefines a lamp body also is disclosed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The objects of the invention are achieved as set forth in theillustrative embodiments shown in the drawings, which form a part of thespecification. In the drawings,

FIG. 1 is view in perspective, partly broken away, of one illustrativeembodiment of lamp assembly of the present invention;

FIG. 2 is a sectional view taken along the line A—A of FIG. 1;

FIG. 3 is a plan view of the circuit board according to an embodiment ofthe present invention; and

FIG. 4 is a block diagram of one illustrative method shown manufacturingthe lamp assembly shown in FIGS. 1 through 3.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF INVENTION

The following detailed description illustrates the invention by way ofexample and not by way of limitation. This description will clearlyenable one skilled in the art to make and use the invention, anddescribes several embodiments, adaptations, variations, alternatives anduses of the invention, including what we presently believe is the bestmode for carrying out the invention. It will nevertheless be understoodthat no limitation in the scope of the invention is thereby intended,and that alterations and further modifications of the illustrativedevices are contemplated, including but not limited to such furtherapplications of the principles of the invention illustrated herein aswould normally occur to one skilled in the art to which this inventionrelates.

Referring now to FIGS. 1 and 2, reference numeral 1 indicates oneillustrative embodiment of lamp assembly of the present invention. Thelamp assembly 1 includes a main body 4, which surrounds a circuit boardor card 6, electrical connectors 8, 10, 12, 14 each attached to theboard 6 with a nut 15, and a plurality of light emitting diodes (LED) 16which together comprise a light emitting unit 52.

Referring to FIG. 3, the circuit board 6 is of conventionalconstruction. However, it preferable that the circuit board 6 defines aplurality of apertures 18. The apertures 18 help prevent gas and/or air,generally in the form of bubbles, from being trapped within the materialwhen the uncured lens material is poured or injected into a mold, asfurther explained below, thereby the preventing the gas and/or airbubbles from being present within the body 4 when the material cures.Also provided are four electrical connector apertures 22 for attachingthe electrical connectors 8, 10, 12 and 14 (8-14) with the nuts 15 tothe board 6. However, while the electrical connectors are shown asfasteners attached to the circuit board 6, electrical connectors 8-14could be wires that extend through the body 4 or a combination of wiresand fasteners. Preferably, electrical connector 8 and electricalconnector 14 are ground connectors and are larger than connectors 10, 12so that the entire assembly 1 may be mounted to a structure, such as avehicle or trailer either as a original equipment assembly or as areplacement assembly for a conventional light. The electrical connector10 may be a taillight connector, which provides for the LEDs 16 toilluminate at a first, dimmer output level, and electrical connector 12may be a stop light connector which provides for the LEDs 16 toilluminate at a second, brighter output level. This may be easilyaccomplished with known methods such as by inserting a resistor in thecircuit providing the lower output level. It can be appreciated by oneof ordinary skill in the art that only one of electrical connectors 8and 14 is required to provide an electrical ground and the one of theelectrical connectors 10 and 12 may be eliminated to provide for only asingle illumination output level. While a male connection is illustratedin FIG. 2, those skilled in the art will appreciate that a female orother interconnection form may be employed, if desired. Finally, thecircuit board 6 may also comprise reflectors 20 attached to the board 6to provide for identification of a parked vehicle or trailerimplementing operation of the light assembly 1 of the present invention,for example, when the same is approached by another vehicle at night.

The LEDs 16 preferably are arranged in rows and columns, as best seen inFIGS. 1 and 3. Various arrangements of the LEDs 16 are compatible withthe broader aspects of the invention, and depend to some measure on theshape of the body 4 and/or the intended use of the lamp assembly 1. Forexample, although a generally rectangular body 4 is shown in thedrawings, those skilled in the art will appreciate that other shapes,including round, elliptical, triangular, emblematic and the like may beemployed in other embodiments of the invention. The configuration of thebody 4 will often determine the arrangement required or permitted of theLEDs 16. Those skilled in the art also will recognize that the LEDs 16need not be arranged in rows and columns or that a single LED 16 may beemployed in other applications of the invention.

The design is unique, for example, because the material used for thebody 4 defines both a lens 54 and the body for the lamp assembly 1 toprovide a solid one piece assembly. Preferably, the body 4 isconstructed from relatively unbreakable material. Tenite cellulosicavailable from Eastman Chemical Company is an acceptable material forthe lamp assembly 1 of the present invention where the light assembly 1is intended for use in boat trailers. As indicated above, that materialhas an impact strength of 4.8 ft-lbs. per sq. inch. In boat trailerapplications, the material thickness may approach one half of inch ormore, for example, a thickness for which specific manufacture's data wasnot available from conventional sources. We have tested other materialin prototype assemblies that have sustained 30 ft. lbs. force on thelight assembly without damage (tested by dropping a five pound weightfrom a height of six feet). Again, the preferred material for anyparticular application is one that does not suffer damage in itsintended application during normal or intended operation of thatapplication. In the context of this specification and invention,“unbreakable” has this meaning ascribed to it. The Tenite cullulosicmaterial initially is flowable, and sets up to a final shape over somepredetermined period of cure time. The method of cure may vary,depending on the material used to form the body 4. For example, somematerial may cure in a satisfactory time merely with an ambient aircure. Other materials may require the application of heat or cold tocure satisfactorily. Regardless of cure, however, all embodiments of theinvention are designed so that the body 4 encapsulates at least the LEDs16 and circuit board 6, and arranged and formed to define the lens 54for the lamp 1. That encapsulation, in turn, provides at least waterresistance properties to the lamp assembly 1, since the material isgenerally impervious to liquid. If care is taken in the manufacturingprocess with the electrical connection to the circuit board 6, the lampassembly 1 easily can be made to be water proof in the conventionalsense of that term.

A preferred method of manufacture is shown in FIG. 4. A suitable mold 40is constructed in a conventional method. The mold 40 is designed so thatlamp assembly 1 has its intended shape upon removal from the mold. Thatis to say, the mold 40 is preformed so that the finished lamp assembly 1may be extracted from the mold directly.

The LEDs are mounted to the circuit board 6 in a step 42. That combinedassembly then is placed in the mold 40 in a step 44. As indicated above,preferably the electrical connections 8-14 are attached to the circuitboard and inserted in the mold simultaneously with the circuit board andLEDs. However, the electrical connection may be made at a later time, ifdesired.

In the embodiment illustrated, the mold 40 also has provisions forproviding one or more openings 36 through the enclosure. Alternatively,the openings 36 may be formed in the assembly 1 after removal from themold. Those skilled in the art will recognize that the openings 36 maybe eliminated in other embodiments of the invention. In any event, afterplacement of at least the LEDs and circuit board in the mold 40, themold is filled with lens material to encapsulate the LEDs and circuitboard completely, as illustratively shown in FIG. 2. Thereafter, thelens material is cured in a step 48 and the essentially finished productis removed from the mold in a step 50.

In order to manufacture the lamp assembly 1 in high volumes, we havemade prototypes through an injection molding process. In using thatprocess, we found that a high number of rejects were obtained becausegas and/or air would become trapped within the lens material during theinjection molding process. While the problem was not present with allshoots of material, it was prevalent enough to make the processuneconomical for large scale production. We have found that providingapertures 18 through the circuit board 6 helps prevents gas and/or airfrom being trapped with the body 4 even when a high speed injectionmolding process is used to form the lamp assembly 1. The apertures 18location and number may vary in embodiments of the invention. We havefound that the number and location of apertures 18 depend in part on thematerial used for the body 4, and the speed and consequently pressure atwhich injection takes place. In addition, the construction of the boardand the electrical component attachment thereto should be designed sothat they do not hinder the flow of material during the injectionmolding process.

Because of the ease of manufacture, those skilled in the art willrecognize that a number of attributes can be obtained with the lampassembly 1 of the present invention. Merely by way of example, one ormore of the rows 12 of the LEDs 16 may emit a different light spectrumfrom the remainder of the LEDs 16. Thus, certain of the LEDs 16 may bearranged to provide a yellow arrow indicating a turning motion for thevehicle, while the remaining LEDs 16 emit a light from the red spectrumindicating when the vehicle brakes are applied, for example. Likewise,the material forming the body 4 may have a color pigment associated withit so that the enclosure 1 has a familiar red brake light configuration,if desired.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results are obtained. Asvarious changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense. Numerous variations, within the scope of the appended claims,will be apparent to those skilled in the art in light of the foregoingdescription and accompanying drawings. For example, as indicated, theenclosure 1 may assume a variety of shapes. In addition to thosedescribed previously, the enclosure 1 may be modified to promote fastcuring of the material used for the body 1. Other materials may beemployed for the enclosure besides that described. The LED arrangementmay vary in other embodiments of this invention. Likewise, the enclosuremay be formed in a lens design, if desired. While the light assembly 1is described as utilizing LEDs, other forms light emitting structuresmay be employed, if desired. Thus, conventional incandescent lamps ordifferent unconventional sources of light may be employed in embodimentsof the invention. LEDs presently are preferred because they offer lowenergy consumption and long life in applicational use. The lightassembly 1 also may be attached to a second structure in a number ofways. Merely by way of example, while conventional threaded fastenersthrough suitable openings work well, the light assembly 1 may be bracketmounted, surface mounted, or recessed mounted in a friction fit, ifdesired. Applications of the light assembly 1 are numerous, and thedescription with respect to boat trailers is not to be construed in alimiting sense.

We claim:
 1. A lamp assembly comprising: a support circuit board, thecircuit board having a first side and a second side, the circuit boarddefining at least one aperture for communication between the first andsecond sides of the circuit board; a plurality of light emitting diodesmounted to the circuit board; an electrical connection attached to thecircuit board and extending outwardly of the lamp assembly; a mold inplace lens formed from material flowable about the circuit board andthrough the at least one aperture to encapsulate the circuit board andlight emitting diodes, to provide a one-piece solid body about saidcircuit board and light emitting diodes, said solid body being formedinto a predetermined shape defining said lamp assembly, the electricalconnection extending outwardly of the lens assembly, said body and saidlens being formed from the same material.
 2. The lamp assembly of claim1 wherein the circuit board defines a plurality of apertures, theapertures positioned to prevent gasses from being trapped within thematerial during formation of the mold in place lamp assembly.
 3. Thelamp assembly of claim 2 wherein the circuit board has a reflectorattached thereto.
 4. The lamp assembly of claim 3 wherein the circuitboard has a plurality of reflector attached thereto.
 5. The lampassembly of claim 1 wherein the LEDs are positioned and arranged in rowsand columns.
 6. The lamp assembly of claim 5 wherein at lease one of therows of LEDs emit light having a color different from at least anotherrow of the LEDs.
 7. The lamp assembly of claim 6 wherein the lensmaterial has at least one opening formed in it for permitting attachmentof the lamp assembly to another structure.
 8. The lamp assembly of claim1 wherein the lamp assembly withstands a force of at least 30 ft.lbs.persquare inch of force without damage.
 9. A lamp assembly comprising: ahousing formed from a moldable translucent material; a lens defined bythe moldable, translucent material forming the lamp assembly; a lightemitting unit attached to a circuit board wherein the circuit board hasbeen molded within the material, the circuit having at least oneaperture formed in it for permitting flow of the translucent materialthrough the circuit board; and electrical leads attached to circuitboard that extend through the material to allow electrical connection tothe circuit board, the housing and lens being formed from the samemoldable, translucent material, the material defining a predeterminedshape for the lamp assembly.
 10. The lamp assembly of claim 9 whereinthe circuit board has reflector attached thereto.
 11. The lamp assemblyof claim 10 wherein the circuit board has a plurality of reflectorsattached thereto.
 12. The lamp assembly of claim 9 wherein the circuitboard defines a plurality of apertures positioned to prevent gassesbeing trapped with the material.
 13. The lamp assembly of claim 9wherein the light emitting unit comprises a plurality of light emittingunit comprising light emitting diodes (LEDs).
 14. The lamp assembly ofclaim 13 wherein the LEDs are positioned and arranged in rows andcolumns.
 15. The lamp assembly of claim 14 wherein at least a portion ofone of the rows of LEDs emits light having a color different from atleast a portion of another row of the LEDs.
 16. The lamp assembly ofclaim 9 wherein the lens material has at last one opening formed in itfor permitting attachment of the lamp assembly to another structure. 17.The lamp assembly of claim 9 wherein the lens material can withstand aforce of at least 30ft.lbs.per square inch without damage.
 18. A lampassembly comprising; a housing; a circuit board defining a plurality ofapertures; a light emitting unit connected to the circuit board; and alens formed from a moldable lens material, said lens material flowablethrough the aperture plurality; wherein the circuit board and lightemitting unit is submerged within the moldable lens material beforehardening and the moldable lens material allowed to harden, such thatthe circuit board and light emitting unit are encased within themoldable lens material in the substantial absence of air, the housingand lens being formed from the same material, the material defining apredetermined shape for the housing.
 19. The lamp assembly of claim 18wherein the light emitting unit comprise a light emitting diode.